Efficient production of bisphenol-A by utilizing cation-exchange polystyrene resins that are cross-linked by naphthalene or a biphenyl unit

Ion-exchange materials are well known for their utilization in the processes of water treatment,1, 2, 3, 4, 5 demineralization,6, 7 water softening,8, 9, 10 ultra purification of water11, 12 and removal of unwanted ions,13, 14 as well as in chemical processing.15 One ion-exchange material is acidic sulfonated polystyrene-divinylbenzene (DVB) cation-exchange resin, which has an important role in the production of bisphenol-A by participating in an acid-catalyzed condensation reaction between phenol and acetone. Bisphenol-A is a very important raw material for the synthesis of epoxy resins and polycarbonates; thus, >400 000 tons of bisphenol-A have recently been domestically produced

Efficient production of bisphenol-A by utilizing cation-exchange polystyrene resins that are cross-linked by naphthalene or a biphenyl unit

Ion-exchange materials are well known for their utilization in the processes of water treatment,1, 2, 3, 4, 5 demineralization,6, 7 water softening,8, 9, 10 ultra purification of water11, 12 and removal of unwanted ions,13, 14 as well as in chemical processing.15 One ion-exchange material is acidic sulfonated polystyrene-divinylbenzene (DVB) cation-exchange resin, which has an important role in the production of bisphenol-A by participating in an acid-catalyzed condensation reaction between phenol and acetone. Bisphenol-A is a very important raw material for the synthesis of epoxy resins and polycarbonates; thus, >400 000 tons of bisphenol-A have recently been domestically produced

Effect of introducing a cyclobutylmethyl group into an onium cation on the thermodynamic properties of ionic clathrate hydrates

Ionic clathrate hydrates (ICHs) have been applied to thermal storage materials, which can be utilized as unusual thermal energy sources. In the present study, we developed a novel ICH including tri-n-butyl(cyclobutylmethyl)phosphonium bromide (P444(1c4)-Br) as an unprecedented guest species. The highest equilibrium temperature and the dissociation enthalpy of P444(1c4)-Br ICH were 279.5 ± 0.1 K and 202 ± 2 J g−1, respectively, at the mole fraction of 0.0255 ± 0.0008. The highest equilibrium temperature of P444(1c4)-Br ICH was slightly lower than that of the tetra-n-butylphosphonium bromide (P4444-Br) ICH. The dissociation enthalpy of P444(1c4)-Br ICH was larger than that of other ICHs with similar highest equilibrium temperatures. Cyclic hydrocarbon groups, together with normal, branched, saturated, and unsaturated hydrocarbon chains, can be one of the options for tuning the equilibrium temperature of ICHs.Reproduced from New J. Chem., 2023, 47, 231-237 with permission from the Royal Society of Chemistry.https://doi.org/10.1039/d2nj04361

Equilibrium Phase Relations and Dissociation Enthalpies of Tri- n-butylalkenylphosphonium Bromide Semiclathrate Hydrates

Semiclathrate hydrates (SCHs) have received attention as thermal storage materials because of their equilibrium temperature and relatively large dissociation enthalpy. The alkyl length of quaternary onium cations significantly affects the equilibrium temperature and dissociation enthalpy of quaternary onium salt SCHs. To investigate the effects of the double bond introduced in onium cations, in the present study, the thermodynamic stability of tri-n-butylalkenylphosphonium bromide (P444(alkenyl)-Br: alkenyl = 3-butenyl (3═1) or 4-pentenyl (4═1)) SCH was investigated. The equilibrium temperatures and the dissociation enthalpies were determined to be (277.5 ± 0.1) K and (199 ± 2) J/g for P444(3═1)-Br SCH, and (274.8 ± 0.1) K and (188 ± 2) J/g for P444(4═1)-Br SCH. The equilibrium temperatures of P444(3═1)-Br SCH and P444(4═1)-Br SCH were lower than those of the corresponding normal alkyl SCHs (P4444-Br and P4445-Br), although the equilibrium temperature of tri-n-butylallylphosphonium bromide SCH was higher than that of the P4443-Br SCH.Azuma S., Shimada J., Tsunashima K., et al. Equilibrium Phase Relations and Dissociation Enthalpies of Tri- n-butylalkenylphosphonium Bromide Semiclathrate Hydrates. Journal of Chemical and Engineering Data, 67, 6, 1415 - 1420, May 25, 2022, © 2022 American Chemical Society. https://doi.org/10.1021/acs.jced.2c00146

Peritectic phase behavior of tetra-n-butylphosphonium trifluoroacetate semiclathrate hydrate

Phase equilibrium (temperature–composition) relations of the tetra-n-butylphosphonium trifluoroacetate (TBP-TFA) + water binary system including solid (semiclathrate hydrate, SCH)-liquid equilibria and liquid-liquid equilibria were investigated. Phase diagram of TBP-TFA SCH exhibited peritectic behavior. The maximum decomposition temperature (peritectic temperature) of TBP-TFA SCH at atmospheric pressure were 275.9 ± 0.1 K. The stoichiometric composition of TBP-TFA SCH was located at the mole fraction of 0.027 ± 0.002. The decomposition enthalpy of TBP-TFA SCH was 199 ± 2 J/g. At temperatures above the lower critical solution temperature (LCST), the liquid-liquid phase separation appeared. Interestingly, the composition at the LCST was 0.026 ± 0.002, which is very similar to the stoichiometric composition of TBP-TFA SCH. It implies that both cluster-based solution structures are similar